Overall objective of the proposed research is to establish what alterations occur in muscle membrane following denervation. After establishing these alterations, attempts will be made to quantitate the differences and determine which alterations are interrelated (e.g., which occurs first and which are secondary) and which alterations are of prime physiologic importance. Specific aims of the research are: 1) to determine the regulation of enzymes likely involved in the metabolism of surface membranes of normal and denervated muscle, and 2) to determine regulation of the synthesis and degradation of surface membrane macromolecular constituents in normal and denervated muscle. Goals for current year included in 1) above: (i) determination of glycoconjugate sialyltransferase activity in denervated muscle and (ii) determination of regulation of increased acid protease activity in denervated EDL muscle; and in 2) above: (i) determination of what muscle proteins were being degraded by the increased levels of protease, and (ii) why and how UDP-glucose was bound less readily by denervated muscle homogenates than control muscle homogenates.